Amnesty Report Accuses Syria of Executing Thousands Since War Began

BEIRUT, Lebanon — The Syrian government has executed 5,000 to 13,000 people in mass hangings in just one of its many prisons since the start of the six-year-old uprising against President Bashar al-Assad, Amnesty International contends in a new report.

The report on the Saydnaya military prison, which Amnesty said was based on interviews with former detainees there, prison employees, judges and others, accuses the Syrian government of systematically executing perceived opponents after sham trials that lasted just a few minutes.

Inmates are kept under conditions so dismal — including regular, severe beatings and deprivation of food, water, medicine and basic sanitation — that they amount to deliberate extermination, defined under international law as a crime against humanity, the report said.

While inhumane prison conditions in Syria have been known for decades, the Amnesty report laid out what it described as new details — not documented by any human rights monitoring group to date — about the scale of the killings and the state systems required to facilitate them, including approvals by high-ranking officials.

“We now know where, when and how often these hangings are taking place, as well as which elements of the Syrian government have authorized them,” said Nicolette Waldman, an Amnesty researcher specializing in detention issues and one of the report’s authors.

Mr. Assad, in an interview with The New York Times and other journalists last year, insisted that detainees were being treated according to Syrian law and that their families could locate them by appealing to the judicial system.

But the report corroborates numerous accounts given to The Times by current and former detainees in several prisons across Syria, detailing regular torture and deprivation. It also echoes reports from families of detainees that the government has refused to provide even basic information such as where they are and whether they are alive.

According to former officials cited in the report, detainees — most of them accused of nonviolent offenses, such as participating in demonstrations — are tortured into giving confessions, then taken to so-called military field courts, where they undergo trials lasting two to three minutes. At regular intervals, the Amnesty report said, they are gathered in the middle of the night from their cells and taken blindfolded to an execution room on the grounds of the prison near Damascus, where they are hanged.

Some prisoners have managed to stand on toilets to look out windows and see bodies carted away, and the number of slippers left lying on the ground. “If there were 30 slippers, then we knew that 15 people had been executed,” Abu Osama, a former military officer detained in the prison, was quoted as saying. “There were usually between 30 and 80 slippers outside.”

A version of this article appears in print on , on Page A6 of the New York edition with the headline: Amnesty Report Accuses Syria of Mass Executions. Order Reprints | Today’s Paper | Subscribe